It works exactly as intended, it has a powerful volume increase and works even over sound equalizer addon!!
I'm on Ubuntu-MATE 20.04 using Firefox 103 PPA from the distro (not a snap).

Thanks a lot developer, I very much appreciate it.

thank you, i do not know already if it works but you made this app, thank you

It don't work in zoom meeting inside the browser

Perfect, just what I needed

Works perfectly, thank you <3

Einwandfrei. Genau das, was ich gesucht hatte. Jetzt kann ich z. B. auch Youtube-Videos, die früher sehr leise waren, vernündtig verstehen.

Muy muy útil!

Thank you! Perfect for YouTube videos with sound in only one ear!